DVT: how to prevent it

My legs tend to swell up on aircraft and I'm fearful of developing a thrombosis. Is it worth taking an aspirin before a flight? Are travel stockings effective? Any other suggestions?

Dr Fred Kavalier answers your health question:

"Economy class syndrome" is supposed to cause deep vein thrombosis (DVT) in long-haul travellers. If you sit for a long time with your legs hanging over the edge of the seat, the blood flow in your leg veins slows right down. The worst scenario is when a blood clot a DVT forms in the legs and shoots off into your lungs as a pulmonary embolus. If you're unlucky, the result is sudden death. Regular exercise of the calf muscles keeps the blood flowing. Compression stockings do work; in one study of air travellers, 10 per cent developed silent DVTs without compression stockings, compared to no DVTs in stocking wearers. The jury is still out on aspirin. Aspirin definitely makes platelets less sticky and this will theoretically make it less likely that you'll get a DVT. Don't take aspirin if it upsets your stomach, and don't give it to children under 12. Another idea is a small exercise cushion you use to keep your ankles moving; the Airogym and the Push Cush are both available on the internet and at travel clinics.

Please mail your questions for Dr Fred to health@independent.co.uk. He regrets that he is unable to respond personally to questions.